Do you ever do heavy lower body work?
e.g.--Back squats, front squats, split squats/lunges, deadlifts, power cleans, power snatches?
If you haven't done these, and you just add in some of that conservatively, you will probably see an instant positive change in body comp, basically like the effect you have when you start benching for the first time. Not just in the legs, either--Squats, deads, and oly lifts throw a load on your back, torso, and whole body in a way that benching doesn't. You might well get a lot of muscle mass and definition out of this initial training.
YMMV but many people on this site will tell you to slowly phase out the grains in favor of fruits and veggies. In my experience this works very well with respect to body comp.